Interaction between MycobacteriuTn tortuitum and Maerophages from the monse peritoneal exudate

Numerous studies on the interactions between microorganisms and phagocytes have suggested that the phagocytosis may be influenced by the nature of microorganisms, the metabolic states of the phagocytes and the physico-chemical nature of environment. etc. Especially, it has been well known that the attachment phase of phagocytosis may be enhanced by the immune sera containing specific antibodies and complements. But information is incomplete or missing on the mode of action of normal homologous and heterologous serum mixed in the medium of in vitro experiments on phagocytosis. Therefore, an experiment was performed to understand the influences of normal heterologous serum on the interaction between mouse macrophages and Mycobacterium /ortuitum which are pathogenic to mice. in the medium with bovine serum as heterologous serum and as a control in the medium without serum components. Thus, normal mouse macrophages were collected from the peritoneal cavity, pooled, suspended in the cell-maintenance medium, and mixed with supension of Mycobacterium fortuitum both in the medium with serum and in the medium without serum. The bacteria-macrophages suspensions in the Leighton tubes with cover-slip were incubated at 37'C, for 120 minutes, and the ratio of macrophages containing AFB to the total macrophages observed in the stained coverslip and viable bacterial counts in the supernatants of the medium in this experimental condition were checked at zero time(as a control), 30 min .. 60 min., 90 min., and 120 min. during incubation. The results obtained in this experiment were summarized as follows; 1. The rate of phagocytosis was more heightened in the medium with serum than that in the medium without serum, i.e, on phagocytosis of mouse macrophages, 2. Until 60 minutes of incubation the macrophagos in the medium with serum phagocytosed Mycobacterium fortuitum twice more rapidly than those in the medium without serum, but no significant difference in the rate of phagocytosis were found at 120 minutes. 3. The phagocytic index at 120 minutes in the medium with serum amounted to 0.4698 when calculated from the viable bacterial counts checked, and half-life of the viable bacterial counts in the supernatant was 71.1· minutes. 4. After 90 minutes of incubation, more than 5096 of macrophages in the stained cover-slip from the medium with serum contained AFB in the cytoplasm

Studies on the Antimicrobic Susceptibility of S. Pneumoniae isolated from Doctorless areas and Seoul.

64 strains of S. pneumoniae isolated from the residents of doctorless areas in Korea from Aug. 1976 to Jan. 1977 and 62 strains of S. pneumoniae isolated from the children in Seoul at Mar, 1977 were examined for susceptibility to 14 antimicrobics by agar dilution method. The susceptibility of two groups to each antimicrohies were compared and incidence of resistant strains in each antimicrobics and correlation in the antimicrobic susceptibility of 126 strains of S. pneumoniae among 14 antimicrobics were analyzed. 1. The mean MIC's of Carbenicillin and Kanamycin to the S. pneumoniae isolated from Seoul were 9.8 and 1. 7 times higher than those to the S. pneumoniae isolated from doctoress areas respectively. 2. There were no significant differences in susceptibility to Penicillin, Ampicillin, Cephalexin, Tetracycline, Oxytetracycline. Doxycycline, Minocycline, Gentamicin, Streptomycin, Erythromycin, Cotrimoxazole, and Troleandomycin respectively between S. pneumoniae isolated from doctorless areas and Seoul. 3. Incidence of resistant strains in S. pneumoniae isolated from doctorless areas was the highest with KanamycinC79.7%) followed by TetracyclineC73. 3%), Oxytetracycline(67.2%), Streptomycin(48.4%) Doxycycline( 42.0%) Minocycline(31. 3%), Gentamicin (28.1%), Carbenicillin (4. 7%) CotrimoxzoleC3.1%), Troleandomycin(I. 6%), and Cephalexin(I. 6%). There were no strains resistant to Penicillin. Ampicillin, or Erythromycin. 4. Incidence of resistant strains in S. pneumoniae isolated from Seoul was the highest with Kanamycin (90.3%). followed by Tetracyc1ine(87.0%) CarbenicillinC74.2%), Oxytetracyc1ineC66. 2%), Streptomycin (61. 3%), Minocycline(33.8%), Gentamicin (24. 2%), and Doxycycline(3. 2%). There were no strains resistant to Penicillin, Ampicillin, Cephalexin, Cotrimoxazole, or Troleandomycin. 5. There were significant differences in the incidence of resistant strains between two groups of S. pneumoniae with Carbenicillin and Doxycycline. 6. There were high correlation in susceptibility of 126 strains of S. pneumoniae among Tetracyline, Oxytetracycline. Doxycycline and Minocyclnet correlation coefficient ranged between 0.86 to 0.95), but there were no significant correlation in susceptibility of S. pneumoniae among Penicillin, Ampicillin, Carbenicillin, and Cephalexin(correlation coefficient ranged between O. 01 to O. 38). Correlation coeffieient of susce-ptibility of S. pneumoniae between Kanamycin and Streptomycin was 0.68